“Flash” Synthesis of CdSe/CdS Core–Shell Quantum Dots

Abstract

We report on the "flash" synthesis of CdSe/ CdS core−shell quantum dots (QDs). This new method, based on a seeded growth approach and using an excess of a carboxylic acid, leads to an isotropic and epitaxial growth of a CdS shell on a wurtzite CdSe core. The method is particularly fast and efficient, allowing the controllable growth of very thick CdS shells (up to 6.7 nm in the present study) in no more than 3 min, which is considerably shorter than in previously reported methods. The prepared materials present state-of-the-art properties with narrow emission and high photoluminescence quantum yields, even for thick CdS shells. Additionally, Raman analyses point to an alloyed interface between the core and the shell, which, in conjunction with the thickness of the CdS shell, results in the observed considerable reduction of the blinking rate.

Fabrication and characterization of on-chip silicon nitride microdisk integrated with colloidal quantum dots

“…It is then etched using a specifically optimized RIE process [13] to obtain smooth and steep sidewalls. The QDs employed in our device are ~10 nm CdSe/CdS core/shell dots prepared according to the "flash" synthesis procedure [15], with a peak PL wavelength around 625 nm. For suspending the disk an alkaline based wet etching step is used.…”

Hybrid Colloidal Quantum Dot Silicon Nitride Waveguide Gain Measurement Based on Variable Stripe Length Method

“…The deposition is performed using an optimized plasma enhanced chemical vapor deposition (PECVD) process at a temperature of 270°C. Then the "flash" synthesized CdSe/CdS core-shell CQDs [4] are spin coated on top of this SiN layer to form a densely packed layer with a thickness of around 70nm. Another 100 nm thick SiN layer is deposited onto the CQDs layer to form the full sandwich layer stack.…”

Doping Group IIB Metal Ions into Quantum Dot Shells via the One‐Pot Decomposition of Metal‐Dithiocarbamates

“…[24,[34][35][36] As-synthesised QDs were analysed using transmission electron microscopy (TEM) and high resolution transmission electron microscopy (HRTEM), with all yielding monodisperse nanocrystals between 3 and 5 nm in diameter (Figure 1). …”